Pivotal connection for shears



Aug. 19, 1952 n D. H. KElsER, JR 2,607,114

PIVOTAL CONNECTION F CR lSHERS Filed Nov. 9. 1949 y INVENTOR. .3a rid/ouzara //'erzfn ttarny Patented Aug. 19,l 1952 ero-7,114

UNITED PIVDTAL CONNECTIQN y DavidlHiKeiser, Jr., WestLawngBaf K YApplicationNovember 9, 1949, ,S ei al No. 125,426' v .1 A'.Cla'illfl- -1My :invention relates .generally to `shears fand, more specifically, toimprovements `particular-1y applicable to the type of shears :shown in.my prior Patent No. Y2,281,977 dated 'May 5, v.1.94.2- My invention isdirected -to the type of shears commonly known asclippergrassshears.infwhich one-.cutting blade is fixed andthe other .ismovable-and my improvements relate more lspecically to .a nonbindingrpivotal connection between vtheshears Vfor insuring a proper :cooperateing .pressure engagement of'the blade cutting edgesduring their closingmovement to providea clean `cut and to prevent.bindngandcloggingof theblades.

.An outstanding Adisadvantage of most 4of the conventional vtypes of`shears ,is that there is .a great tendency for the cutting edges of-thezblades to separate .when Vthey are brought Ytogether .in contactwith .thegoodsto be cutand tobe clogged with uncut material, therefore`not forming .a clean .cut .or shearing action. While `attempts havebeen made to overcome this tendency, and to 'bring the blades closetogether when .brought in contact with .the grass or other materialvbeirut cut, these .attempts Vhave .not generally met .with success .andin most instances vhave .resulted-fin very Acomplicated andexpensive-cons`tructions.

An object of .my invention is to provide a pair of shears which embodiesa relatively simple and inexpensive construction .for providing easy andelective cuttingV action with a more positive and longer wearingpivotalconnection 'having a minimum of friction.

A more specific .object of this invention is to provide a novel clippergrass .shears construction which ,enables the movable blade to be-sli-ghtly rocked whenengaged with the .material .tol be` out. therebybringing its cutting edgein close-engagement with that of thestationaryblade through-A out their entire'lengths to form a clean cutor shearing action, which rocking movement of the movable blade iscaused by the resistance of the grass or other material being cut.

Other objects and advantages of my invention will become apparent from astudy of the following specification, taken with the accompanyingdrawing wherein:

Fig. 1 is a top view of a pair of clipper grass shears embodying theprinciples of my invention;

Fig. 2 is a longitudinal sectional view taken along line II-II of Fig.1;

Fig. 3 is an enlarged transverse cross-sectional view taken along lineIII--III of Fig. l showing the lateral tilting of the movable bladeduring the blade closing movements, and

(ci. staats) '.lig. 4 is .a transverse .cross-sectional identical :tofing. .3 but showing the str ee .moves ment .of `.the blades .duri-ng:their opening maven ments.

fReferring more :particularly ftoV Athe figures., numeral :I .denotesA-a stationaryblade having integrally iiormed at oneend :thereoiavhandled; A Ycooperating :handle: :3 :has integral :upstand-i-ng ears:Bawithaperturesatlthe end-portions thereof through :which extends La..pin .4 v:for .-pylol'zally mounting vhandle .z3-.with :respect ttoVhandle :2. A helical spring g5 is .providedchetween handles 2.and 3 ltobiaslthem aDBfxt.

A pivot :stud 3b... is integrally formed :on and `projects :from one-side .tof handle .311Go .for-in a pivotal connection with an .angle.'fbraoket 6, the other -end .fof `which fbracket :is .connected to thethreaded :shank :portionfofA link .1 fastened tothe bracket ,f5 `in ,any.adjustable .position by means of a nurI 8. The other endof ithe flinkIhasean veye portion which encompasses .aspivotstud Saintegrally 'formedon .the :blade `carrying plate :59. Plate 9 is rigidly .secured such .asby .meansxof rivets I Il ror other .suitable rfastening .means .tofa

movablezbladeill,

Aintegrally formed on -plate'isa boss I2 whose upper opening I 2a .is.of. smaller .diameter VI'han.tits lower opening I2b. Apivpttpostslghasits .lower end rigidly `fixed :to stationary blade I l.andits uppervend-extending through-and .slightly spaced from-:opening tzafsoastopermit .a .slghtrockne or .tilting movement :ofthe fbo'ss with .srespect@to the post.- .AnutIA-:is screw threaded to thetop of the .post :forholding 4posts yin .assembled position. The nut is not tightlyscrewedlonto boss I2 but, instead, a spring I5 is preierably interposedbetween the .nut .and loess asfshewn, whiohfproperly 1t usic thegbcssaea'nsttco tres movement whileipermittmeiitstilt' l. desl'md,

:In operation. fthe movable yblade .is-.moved towards fixed blade I bycompressing handle members 2 and 3 resisted by the compression of spring5. The pivotal movement of handle 3 about pin 4 will cause a pull onangle bracket 6 and link 1. And by virtue of the pivotal connection oflink 1 to the blade carrying plate 9, movable blade II is rotatedloosely about post I3 as an axis. As the result of resistance offered bygrass or other material being cut, movable blade II would have atendency to lift away from blade I about post I3 as a pivot were it 'notfor the rearward extension 9b on blade carrier 9, which extensionslidably engages the rear top surface portion of the fixed blade I. Inorder to reduce friction on such rear top surface portion,

the bottom surface of extension 9b is hollowed out so that only apointed rear edge engages the top of blade I. An extension 9c serves asa stop'- member for limiting the closing movement of the movable blade.Due to the relatively loose :fit of boss l2 with respect to the post I3and. more particularly, to the larger diameter of the Well thereinadjacent the lower portion of the post. and further due to the fact thatthe pulling action by link 1 on blade carrier 9 occurs along the base ofthe boss I2, the grass or other material being cut will oier suchresistance as to form a pivot upon which movable blade H will cant ortilt laterally in a direction so that its cutting edge will come intovery close engagement with the corresponding cutting edge of the xedblade.

This will be more apparent from a'comparison of Fig. 3 and Fig. 4, theformer showing the blade in the tilted position during the cuttingoperation and the latter showing the movable blade in a reversely tiltedposition as the blades are being spread apart by the action of spring 5.The loose pivotal connection therefore permits substantiallyfrictionless movement of blade. II in both directions so as to reducethe force necessary to operate the shears. .As the blades are movedtogether and movable blade I l is tilted or canted laterally,cooperative pressure engagement of the blade cutting edges is eiected tocause a cleanl cutting action, with relief of such pressure duringopening movements thereby reducing wear and preventing binding andclogging ofthe blades.

While the preferred type of shears shown in the drawing has handlesoperating in a plane perpendicular to the horizontal plane of movementof the blades, this is not essential, and any other known suitableoperatingmeans may be used, the present invention relating essentiallyto the novel pivotal connection of the blades and the resulting improvedcutting action.

Thus it will be seen that I have provided an eicient pair of shearsespecially useful for cutting grass, trimming lawns, hedges and t-helike, which is of such construction as to be easy to opcrate and whichwill provide very effective cutting action witha minimum amount offriction, with practically no tendency for theimaterial being out to becaught or clogged between therbllades.

While I have illustrated and described a certain speciiic embodiment ofmy invention, it will be understood that this is by wayV of illustrationonly, and that various changes andmodiiications may be made within thecontemplation of my invention and within the scope of the followingclaim.

I claim: A f Y Grass shears comprising a pair of pivotally connectedblade means, a loose pivotal connection therefor comprising a bossintegrally formed on and extending vertically outwardly from the planeof one of said blade means, a pivot bolt extending through both of saidblade means and through said boss, sai-d boss being substantiallycup-shaped and spaced radially from the bolt throughout the majorportion of the height of the boss and terminating at its other end in aradially inwardly extending bearing portion closely itted about the boltwith a hole considerably smaller than the base forming mouth portion ofthe boss whereby the boss can be tilted relative to said bolt about saidbearing portion as a pivot, said bolt having a cap part Iat the endthereof overlying said bearing portion of the boss,

said base forming mouth portion of said boss plane at right angles tothe plane of said blades,

a pair of pivotally connected handles for pivotally moving sa-id blademeans, spring means mounted between said handles for normally spreadingsaid handles apart, said one of said blade means having an extensionprojecting laterally of its blade, an operating link having one endpivotally mounted on said extension and the other end pivotally mountedon one of said 'handles, said link being movable in a plane extendingrearwardly of and substantially parallel to said bearing forming portionof said boss, whereby as the handles are operated to pul1 said operatinglink, said last mentioned blade means will cant to effect closeengagement of the cutting edges of the blades of said blade meansthroughout their shearing movements; a stop forming extension integrallyformed on one of Said blade means and engageable with the other of saidblade means to limit closing movement of the blade means, and a helicalspring surrounding said pivot bolt and normally biasing said blade meansinto engagement.

' DAVID H. KEISER, JR.

REFERENCES CITED The following references are of record in the nie ofthis patent:

UNITED STATES PATENTS SmOllSen Dec; 29, l194.2

